In recent years, the number of dementia patients has increased as the aging of society advances. Nowadays, as much as two millions of patients in the country are estimated to be suffering from dementia. Dementia causes memory impairment, disorientation, learning impairment and the like that considerably interfere with everyday activities. In addition, problematic behavior such as ranting, violence, wandering, and dirty behavior may be seen in some cases. Furthermore, at a late stage, mobility impairments such as brachybasia and forward-bent posture are exhibited. Finally, dementia patients end up in a bedridden state.
In addition to three major dementias, i.e., Alzheimer's dementia, cerebrovascular dementia, and Lewy body dementia, dementia includes mobility impairment such as Parkinson's disease. Furthermore, in another case of dementia, a cognitive function declines in conjunction with mental disorder such as depression and schizophrenia. If the type of dementia can be determined by diagnosis, medical treatment appropriate for the determined type, such as medicinal treatment, can be then provided. In any type of dementia, early detection and appropriate medication can restrain progress from a mild state. In view of these aspects, a screening test for detecting dementia at an early stage needs to be conducted on healthy older people who are highly likely to become demented.
Major diagnosis for dementia is conducted by a test for checking a cognitive function such as memory and judgment, as in the Hasegawa's Dementia Scale and mini mental state examination (MMSE). Nevertheless, these diagnostic approaches require several minutes through several tens of minutes of face-to-face examination by a doctor. Thus, these diagnostic approaches cannot be suitable for a screening test to be conducted on numerous patients.
In addition, diagnosis based on cerebral image measurement is conducted. For example, there is a method for screening for the presence of brain shrinkage using Computed Tomography (CT) or Magnetic Resonance Imaging (MRI), and a method for examining the accumulation status of amyloid beta, which is a causative substance of dementia, using Single Photon Emission Computed Tomography (SPECT) or Positron Emission Tomography (PET). Nevertheless, these kinds of cerebral image measurement need high test cost, and require long test time. Thus, such diagnosis cannot be suitable for a screening test to be conducted on numerous patients.
In light of these problems, for example, PATENT LITERATURE 1, PATENT LITERATURE 2, NON PATENT LITERATURE 1 and the like disclose examples of an evaluation system for easily evaluating a cognitive function of a subject without depending on a doctor, by using a tablet computer equipped with a touch panel sensor.